Fat loss and muscle gain use the same framework. Protein high. Fat adequate. Carbs fill the rest. What changes is total calories and, on the margin, the fat-to-carb mix. Here's the playbook for each.
Fat loss: TDEE − 400
Cut 300–500 calories below TDEE. For a 180 lb adult at 2,700 TDEE, that's 2,200–2,400 calories per day. Expect 0.5–1 lb of weight loss per week. Most of it fat, if protein is high and training is present.
- Protein — 0.8–1.0 g per lb bodyweight (144–180 g for a 180 lb adult).
- Fat — 0.3–0.4 g per lb (54–72 g).
- Carbs — whatever's left after protein and fat.
Muscle gain: TDEE + 250
Add 200–300 calories above TDEE. For the same 180 lb adult at 2,700 TDEE, that's 2,900–3,000 calories per day. Expect 0.25–0.5 lb of weight gain per week. About half should be muscle if you're training seriously (lifting 3–5× per week).
- Protein — same target: 0.8–1.0 g per lb (144–180 g).
- Fat — 0.3–0.4 g per lb, same floor.
- Carbs — higher than on a cut, because total calories are higher. Carbs fuel training intensity.
Maintenance: TDEE
Eat your TDEE. Used for phases between cuts and bulks (called "maintenance breaks" or "diet breaks"), and for long-term body-composition goals once you're at your target weight.
What stays constant
- Protein target. Same g/lb for all three phases. Non-negotiable.
- Fat floor. Don't drop below 0.25 g/lb during a cut — hormones suffer.
- Training. Resistance training drives body composition regardless of calorie phase.
What changes
- Total calories. The main lever.
- Carb intake. Higher on bulks because there's more total room.
- Meal frequency preference. Bigger meals are harder to fit on a cut (volume-eater strategies help); easier on a bulk.
- Adherence difficulty. Cuts are harder. You're hungry. Bulks are easier — though appetite-forcing during long bulks is its own challenge.
Pick lose / maintain / gain. Calorie target adjusts, protein stays constant. Shareable URL for the plan.